Slug casting machine



June 27, 1939. w. PETE RSEN SLUG CASTING MACHINE Fild May 26, 1937 v 5 Sheets-Sheet 1 INVENTOR A TTORNEY w. L. PETERSEN SLUG CASTING MACHINE June 27; 19 9.

' Filed May 26, 19:57

5 Shee ts-Sheet 2 I v [a INVENTOR BY W g A romw m June 1939- w. L. PETERSEN SLUG CASTING MACHINE Filed May 26, 1937 5 Sheets-Sheet 3 INVENTOR BY 76 2 7 1 7/ ATTORNEYJ June 27, 1939.-

w. L. PETERSEN SLUG CASTING MACHINE 5 Sheet s-Sheet 4 Filed May 26, 1937 f INVENTOR BY (in M W V i1 Trozezvzm 'June 27, 1939. PET N 2,163,848

sLue CASTING MACHINE Filed May 26, 1937 5 Sheets-Sheet 5 EE S E M .1. I Tim? 1? r M i, f {k 9 h INVENTOR A TTORNE Ya Patented June 27, 1939 PATENT OFFICE SLUG CASTING MACHINE William L. Petersen, Springfield, N. Y., assignor to Mergenthaler Linotype Company, a corporation of New York Application May 26, 1937, Serial No. 144,839

Claims.

This invention relates to slug casting machines, such as Linotype machines of the general organization represented in United States Letters Patent to O. Mergenthaler, No. 436,532, whereas in a melting pot is arranged to deliver molten melt into a slotted mold and up against a composed line of matrices to produce a type bar or slug bearing on its edgetype characters corresponding to the intaglio characters of the matrices.- In these machines, the molten metal is introduced into the mold by means of a springactuated pump piston or plunger arranged within the pot and controlled in its action by a rotary cam which, as well known, makes one completerotation for each cycle of operation of thema chine. The cam is so shaped as normally to maintain the pump plunger in a raised position out of action, but at 'one portion of its circumference it is formed with a depression which at the proper time permits the plunger to descend under the influence of its actuating spring to force the metal into the mold,,it'being understood in this connection that the distance the plunger descends or its effective stroke is largely determined by the amount of metal it displaces rather than by the depth of the depression in the cam. Since the slugs produced inthe modern machines vary widely in size (both as regards length and thickness), it is evident that the effective stroke of the plunger Will varycorrespondingly, assuming, of course, that the 'metal be kept at a constant level within the pot; Thus, when casting short slugs of the thinner variety, the plunger descends only a short distance as compared with the distance it is required to travel when casting long slugs'of the'thicker variety. In practice it has been found that this variable condition frequently leads to the casting of defective slugs. The difiiculty is that oftentimes the actual casting to congeal or solidify before the return stroke of the pump plunger, which, under such circumstances, exerts a suction effect and draws some of the metal from the mold back into the pot. Thecondition becomes more aggravated in the case of the larger slugs which, not only require-a greater volume ofmetal and therefore a greater time for cooling, but which in addition necessitate a longer effective stroke of the pump plunger and correspondingly less time before it begins its return stroke.

The present invention is intended to overcome these and other objections and contemplates automatic means for delaying the return stroke of the pump plunger for a predetermined interperiod is too short to permit the molten metal val after'the mold has been filled with molten metal to allow additional time for the metal to solidify before the pump pressure is removed. In

the present embodiment, the machine is equipped with a driving pinion and a driven gear mounted 5 on the cam shaft, the driven gear having a mutilated portion which arrives opposite the driving pinion as the depression in the pump plunger cam (which permits the active stroke of the plunger) arrives in operative position. The result is that the driving pinion ceases to drive the cam shaft, thus permitting the pump plunger to pause for a definite period at the end of its active stroke. The duration of this pause is de termined by a segmental gear which overlaps the mutilated portion of the driven ganand which in turn is adapted to mesh with and be driven by the driving pinion. Normally, thesegmentalgear is carried along by the driven gear, but when the mutilated portion of the latter arrives opposite the driving pinion, the driving pinion then engages the segmental gear and causes the latter to rotate through a limited arc, allowing the main driven gear to remain stationary temporarily. Thereafter, an abutment on the segmental gear engages the driven gear and causes the latter to rotate until the mutilated portion thereof is carried past the driving pinion, enabling the latter again to actuate the driven gear. As the segmental gear passes out of the range of the driving pinion, a detentefiects its arrest momentarily until it is again picked up by the driven gear through the engagement of a portion of the latter with an abutment on the segmental gear. The segmental gear is spring- 235 held in this position (which is its normal one) with respect to the driven gear during the completion of the machine cycleand until it is again actuated in the succeedingmachine cycle. In

other words, the segmental gear has a limiteddegree of lost motion relativeto the driven gear, a

and it is this lost motion which determinesthe extent of the pause during which thepump plunger is allowed to remain at the bottom of its active stroke. 7 fTheinvention also contemplates means for varying the extent of the lost motion of the segmentalgear and'consequently the duration of the pause for slugs of different sizes. It will be un- '50 derstood that for small slugs, no pause in the operation of the machine is necessary, and accordingly means are provided for coupling the segmental gear in such cases to the driven gear, so that the rotation of the latter will be continuous or uninterrupted throughout the casting cycle.

In the accompanying drawings, the invention has been shown merely in preferred form and by way of example as applied to a Linotype machine, but obviously many changes and alterations may be made therein and in its mode of adaptation without departing from its spirit. Generally speaking, it is to be understood that the invention is not limited to any specific form or embodiment, except insofar as such limitations are specified in the appended claims.

Referring to the drawings:

Fig. 1 is a side elevation, partly in section, of the casting mechanism constructed in accordance with the invention, and showing the parts in theirnormal position of rest;

Fig. 2 is a side elevation of the driven gear and segmental gear assembly, showing the parts in a position wherein the mutilated portion of the driven gear has arrived opposite the driving pinion;

Fig. 3 is a View similar to Fig. 2, but showing the parts in a position wherein the segmental gear is engaging the driven gear to move the mutilated portion of the latter past the driving pinion;

Fig. 4 is a view similar to Fig. 2, but showing the parts in a position wherein the segmental gear has moved past the driving pinion and has been brought to rest;

Fig. 5 is an elevation of a portion of the mechanism shown in Fig. 4, and illustrating the parts immediately after the driven gear has picked up the segmental gear for the completion of the machine cycle;

Fig. 6 is a transverse vertical sectional view on line S e of Fig. 3; and

Fig. 7 is a sectional view on line 'll of Fig. 2.

In Fig. 1, the parts are shown in the relative positions they occupy just prior to the commencement of the slug casting operation, the slotted mold A carried by the rotary disc A being closed at the front by the composed line X, which is presented momentarily thereto by the first elevator B, and at the rear by the mouthpiece of the melting pot C, which contains a supply of .type metal maintained in a molten condition by means of a suitable burner or heater (not shown). The pot C is formed with a throat or passage C through which the molten metal is forced into the mold by a spring-actuated plunger D, the latter being arranged to recipro cate within the pot well or cylinder C communicating with the throat C The plunger D is connected by means of a rod or link D to the long arm of a bell-crank lever D having a sleeve portion D journalled on a fixed transverse rod D of the machine frame and provided with an arm D? extending laterally beneath a second lever D which is also j-ournalled on the rod D? and connected at its free end to a pull spring D The latter is anchored tothe machine frame and actuates the plunger D through the connections just described. The shorter arm of the bells crank D is provided with a roller D arranged to track upon the periphery of the usual rotary cam D fast to the main shaft of the machine. As well understood, the peripheral face of the cam D is concentric throughout, except at one portion of its circumference where it is cut away or formed with a' depression D When the machine is at rest, the roller D is in contact with the concentric portion of the cam D, so

that the plunger is maintained in its raised-or inoperative position, as shown in Fig. 1. This condition obtains until the casting period arrives, when the cam rotating in the direction indicated brings the downwardly sloping surface at of the depression D into engagement with the roller D which then quickly descends along such surface toward the bottom of the depression, thus permitting the spring D to depress the plunger and force a charge of molten metal into the mold. As the cam continues to rotate, the roller D is engaged sooner or later by the upwardly sloping surface d of the depression D and the parts thereby more gradually restored to their original condition to await the next casting operation.

The parts so far described, and their construction and mode of operation, are or may be the same as those embodied in the commercial Linotype machine and in themselves constitute no part of the present invention.

It will be understood that, during the slug casting period, the roller D will ordinarily seldom reach the bottom of the depression D due to the fact that the plunger D will be arrested in its descent at one level or another according to the volume of metal it displaces in effecting the cast. The shape of the depression D it will be observed, provides for no'dwell of. the roller D therein, except insofar as the distance through which the roller enters the depression causes a delay in theengagement of the roller by the sloping surface 05 of the cam which efiects the ascent of the pot plunger, and this delay, indeed, will be shorter, the larger the slug cast, since the deeper the roller D enters the depression D the sooner will the sloping surface d commence the ascent of the plunger. The result is that for the larger slugs, the pump plunger D starts to ascend before the metal has congealed in the mold A, and consequently sucks some of the metal from the mold back into the melting pot, thus producing imperfect slugs. In accordance with the present invention, it is proposed to delay or effect a pause in the ascent of the pump plunger D, so as to give the metal sufiicient time to congeal properly in the mold, this delay 'or pause being effected in the instant case by arresting the operation of the machine-and hence the rotation of the'cam shaft'as the plunger begins its active stroke.

Before describing the mechanism for eifecting the pause just referred to, it might 'be stated that, as usual, the mainshaft M of the machine on which the pump plunger cam D is mounted, is rotated by a driving shaft M through the medium of a driving pinion M fixed thereon and a driven gear M fast to the main shaft M. Ordinarily, during each machine cycle of operation, the driven gear M is rotated continuously throughout a single rotation of the cam shaft M. According to the present improvements however, this gear, in a sense, is mutilated to the extent that it has a portion M where three of of operation can be completed. The driven gear restarting mechanism includes devices which operate to move the'mutilated portion M of the driven gear 'M past the driving pinion, so that the driven gear again meshes therewith.

The restarting mechanism, j ust' alluded to, in-

cludes a segmental gear N (see Fig. 6 freely mounted on the main shaft M'and arranged for rotationalmovement relative to the driven gear M The outer portion of the segmental gear is offset, so as to bring its peripheral edge adja- .M this position being determined by an adjustable screw N threaded through a lug N screwed to one face of the segmental gear and abutting against a spacing sleeve E which forms part of. the means which secures the cam assembly E to the driven gear 'These respective positions of the segmental gear N and the driven gear M are-maintained by atension spring N partially encircling the hub of the segmental gear and anchored atone end to said gear and at its oppositeend to one of the cams of the cam assembly E. v

Shortly after the. slug casting operation is started, the depression D in the cam D arrives opposite the roller D permitting, as previouslystated, the plunger D to descend under the .action of its spring D to force metal into the mold. Simultaneously therewith, the mutilated portion M of the driven gear M arrives opposite the driving pinion M 1. e., in the position shown in Fig. 2, whereupon the rotation of the main shaft M ceases. Atathis time, however, the segmentalgear has meshed with the driving pinion and, although, as before noted, the driven gear is now stationary, the rotation of the segmental gear continues in the direction indicated by virtue of the lost motion connections between .the two. I

The segmental gear N continues its rotation alone until it reaches the position shown in Fig. 3, wherein a set screw N, which is threaded into a lug N projecting from the face of the segmental gear opposed to that which presents the abutment N (see Fig. 6), engages one of the spokes of the driven gear M It will be noticed that the engagement of the spoke of the driven gearby the screw N occurs before the .teeth at the trailing end of the segmental gear N leave the driving pinion M ,-so that, as the driving pinion continues to rotate the segmental gear, the latter will, through the devices just described, restart the rotationof the driven gear -M to move the mutilated portion M thereof past the Q driving pinion.v The rotation of the driven gear thereupon continues, being now driven directly by the pinion until the machine cycle of operation is completed. j

As the segmental gear N passes beyond the driving pinion M its motion is arrested (see Fig. 4) by the engagement of a spring-pressed detent 0, arranged in a bracket 0 fixed to the machine frame; in-a'recess' N presented in the bottom face of the-lug N in whichthe abutment N is threaded, and this position of the segmental gear is maintained until'th'e continued rotation of the driven gear M brings the sleeve E into engagement with the abutment N (see Fig, 5)-. Thereupon, the segmental gear-N is carried along with the driven gear'M the detent 0 being moved out of the recess N this function being readilyaccomplished as a result, of, the relative configurations ofthe recess and the detent at its outer end. It might be stated here that the detent 0 includes a large head portion 0 slidably arrangedin a long cylindrical recess 0 and a smaller portion 0 encircled by a comthe detent and the base of the recess, said smaller portion extending through the base of. the recess and having a plurality of nuts 0 threaded thereon, by means of which the upper end of the detent can be properly located. It might also be stated that the lug N on the segmental gear' is provided with a bevelled surface N which en gages the detent and serves to depress the same,

so that it will ride beneath the lug and enter in the casting cycle to allow even the largest slugs properly to congeal in the mold and, for slugs of different sizes, the duration of the pause can be regulated by the adjustment of the set screw N since obviously different adjustments of the set screw will vary the degree of relative movement between the segmental gear and the driven gear. The various adjustments of the set screw N are maintained by a lock nut N. The banking screw or abutment N is also adjustable, so as to insure perfect alinement between the teeth of the segmental gear and the teeth of the driven gear; the adjustment of this screw like-.- wise being maintained by a similar lock nut N It will be understood that when casting small slugs, the pause in the casting cycle will not be 1 pression spring 0 reacting between the head of v necessary and, for this reason, mechanism isv cludes a pin P mounted in the segmental gear and arranged to be moved transversely thereof into a hole M formed in the driven gear M and which registers with the pin when the segmental gear and the driven gear are in their normal relative positions. When the pin is moved toward the right from the positionshown'in Fig. 6 into the hole M the two gears are coupled together and will act as a unitary driven gear, the. teeth of which are continuous or uninterrupted throughout its periphery. The different positions of adjustment of the coupling pin P are maintained by a spring-pressed detent P arranged to engage in one or another of'a pair of recesses 1 in the depending upon its headed screw P which passes through a slot mental gear.

Having thus described my invention, what I claim is:

1. In a slug casting machine, the combination of a'mold, a pump plunger for filling the mold with molten metal under pressure, and automatic means actuated at different periods independently of the pump plunger for delaying the return stroke of said plunger after the mold has been filled with molten metal to allow additional time for the metal to solidify before the pump pressure is removed.

2. In a slug casting machine, the combination of a mold, a pump plunger for filling the mold with molten metal under pressure, and automatic means actuated at different periods independently of the pump plunger for creating a pause in the operation of the pump plunger after its mold filling stroke to allow additional time for the molten metal to solidify before the pump pressure is removed.

3, In or for a slug casting machine embodying a main cam shaft, driving means for said shaft comprising a driving gear, a mutilated driven gear fast to the camshaft, and a segmental driven gear having a limited lost motion with respect to the mutilated gear and overlapping the mutilated portion thereof.

4. In or for a slug casting machine embodying a main cam shaft, driving means for said shaft comprising a driving gear, a mutilated driven gear fast to the cam shaft, and a segmental driven gear having a limited lost motion with respect to the mutilated gear and overlapping the mutilated portion thereof, the extent of the lost motion being variable to correspondingly vary the period of interruption in the rotation of.

the driven gear.

5. In or for a slug casting machine embodying a main cam shaft, driving means for'said shaft comprising a driving gear, a mutilated driven gear fast to the cam shaft, a segmental driven gear having a limited lost motion with respect tothe mutilated gear and overlapping the mutilated portion thereof, and a spring tending constantly to hold the segmental gear in its normal position with respect to the mutilated gear.

6. In or for a slug casting machine embodying a maincam shaft, driving means for said shaft comprising a driving gear, a mutilated driven gear fast to the cam shaft, a segmental driven gear having a limited lost motion with respect to the mutilated gear and overlapping the mutilated portion thereof, a spring tending constantly to hold the segmental gear in its normal position with respect to the mutilated gear, and a yielding detent to hold the segmental gear temporarily in a stationary position at the end of 'its lost motion stroke. 1

'7. In a slug casting machine, the combination of a mold, a pump plunger for filling the mold with molten metal under pressure, and automatic means for creating a pause of definite duration in the return stroke of the pump plunger after the mold has been'filled irrespective of the extent of its mold filling stroke.

S; In or for a slug'casting machine embodying a main cam shaft, driving means for said shaft comprising a driving gear, a mutilated driven gear fast to the cam shaft, and a segmental gear having a limited lost'motion with respect to the mutilated gear, said segmental gear acting to move the mutilated portion of the driven gear past the driving gear after the lost motion between themutilated gear and the segmental gear has been taken up. a 7

9. In or for a slug casting machine embodying a main cam shaft, driving means for said shaft comprising a driving gear, a mutilated driven gear fast to the cam shaft, a segmental gear having a limited lost motion with respect to the mutilated gear, and means on the segmental gear acting to engage the driven gear to move the mutilated portion thereof past the driving gear after the lost motion between the mutilated gear and the segmental gear has been taken up.

10. In or for a slug casting machine embodying a main cam shaft, driving means according to claim 9, wherein the means on the segmental gear are adjustable to vary the degree of lost motion between the mutilated gear and the segmental gear.

11. In or for a slug casting machine embodying a main cam shaft, driving means for said shaft comprising a driving gear, a mutilated driven gear fast to the cam shaft, a segmental driven gear having a limited lost motion with respect to the mutilated gear and overlapping the mutilated portion thereof, and means for coupling the segmental gear and the mutilated gear together when a continuous drive of the cam shaft throughout a casting cycle is desired.

12. In or for a slug casting machine embodying a main cam shaft, drivingmeans for said shaft comprising a driving gear, a driven gear fast to the cam shaft and having a'mutilated portion adapted to arrive opposite the driving gear at an intermediate stage of the machine cycle so as to effect a pause in the rotation of the cam shaft, and means acting. automatically and after a predetermined period to move the mutilated portion of the driven gear past the driving.

gear so as to restart the rotation of the cam shaft to complete the machine cycle.

13. In a slug casting machine, the combination of a mold, a pump plunger for filling the mold with molten metal under pressure, operating means therefor, and automatic means independent of the pump plunger for stopping and restarting the plunger operating means at different with molten metal under pressure, operating means therefor, and automatic meansindepe'ndent of the pump plunger for stopping the plunger operating means during the efiective stroke of the pump plunger and for restarting it at a later predetermined period.

15. In a slug casting machine, the combination of a mold, a pump plunger for filling the mold with molten metal under pressure, operating means therefor, and driving means for the. machine, said driving means including. devices operative automatically and independently of the pump plunger to stop and restart the plunger operating means at different periods after the pump plunger has begun its mold filling stroke and before the machine hasjcompleted its normal cycle. V

' 16. In a slug castingv machine, the combination of a mold, a pump plunger for filling the mold vn'th molten metal under pressure, operating means therefor, and driving means for the machine, said drivingmeans' including devices operative automatically and independently of the pump plunger to stop the plunger operating means during the effective stroke of the pump plunger and for restarting it at a later predetermined period.

17. In a slug casting machine, the combination of a mold, a pump plunger for filling the mold with molten metal under pressure, and driving means for the machine, said driving means including devices operative automatically at different periods independently of the pump plunger to establish a pause in the operation of the pump plunger.

18. In a slug casting machine, the combination of a mold, a pump plunger for filling the mold with molten metal under pressure, operating means therefor, and driving means for the machine, said driving means including devices operative automatically at different periods independently of the pump plunger to establish a pause in the operation of the plunger operating means suflicient to delay the return stroke of the pump plunger after the mold has been filled with molten metal.

19. In or for a slug casting machine embodying a main cam shaft, driving means including devices operative automatically at different periods independently of the pump plunger to establish a pause in the rotation of the cam shaft at a predetermined period in and before completion of its normal cycle of operation.

20. In or for a slugcasting machine embodying a main cam shaft, driving means including devices operative automatically at different periods independently of the pump plunger to establish a pause in the rotation of the cam shaft during and before completion of the casting cycle of the machine.

WILLIAM L. PETERSEN. 

